CPT code 81338: MPL testing, common variants2026 Medicare lab fee · Clinical Laboratory Fee Schedule
MPL common-variant analysis detects selected gene changes and supports evaluation of suspected myeloproliferative disorders, including essential thrombocythemia and myelofibrosis.
Medicare pays $150.33 for 81338 under the 2026 Clinical Laboratory Fee Schedule: one national amount, the same in every state and setting.
Medicare lab fee · CLFS 2026 Q4
National CLFS amount
$150.33
In effect since Jan 1, 2026. The same amount in every state, payment locality and setting.
- Geographic adjustment
- None
- Office vs facility
- Same
- Since 2021
- Unchanged
- CMS updates
- Quarterly
Medicare pays the lesser of the lab’s charge and this amount. Patients usually owe no Part B deductible or coinsurance for covered clinical lab tests.
On this page 8 sections
What 81338 covers
This test analyzes common variants in MPL, the gene that encodes the thrombopoietin receptor. Targeted changes include variants at codon 515, such as W515A, W515K, W515L, and W515R. Results can support evaluation of myeloproliferative disorders, including suspected essential thrombocythemia or myelofibrosis. Clinical laboratories perform and report the molecular analysis for ordering clinicians, including hematologists.
Report 81338 when the analysis targets common MPL variants; 81339 describes MPL exon 10 sequencing. Medicare pays this test only under the Clinical Laboratory Fee Schedule (CLFS), not the physician fee schedule. The 2026 national CLFS amount is $150.33, unchanged since 2021. Medicare applies one national amount across states and localities, without geographic or office-versus-facility adjustment.
This summary was written with AI assistance from CMS Clinical Laboratory Fee Schedule data. Amounts on this page come directly from CMS files.
How Medicare pays 81338
Clinical lab tests aren’t priced like physician services. They’re paid from their own fee schedule, with its own rules. See the whole lab fee schedule.
One national amount
CMS sets a single Clinical Laboratory Fee Schedule amount for 81338. There’s no geographic (GPCI) adjustment, so it pays the same in every state and payment locality.
No office or facility rate
Lab tests aren’t built from relative value units, so there’s no office and facility split: the place of service doesn’t change the CLFS amount.
Updated every quarter
CMS republishes the CLFS each quarter. New tests, often proprietary laboratory analyses (PLA codes), join during the year; existing amounts are updated each January.
Excluded from the physician fee schedule
The physician fee schedule lists 81338 with status X (excluded by statute), so the test itself is paid only from the CLFS.
81338 on the lab fee schedule since 2021
81338 · CLFS 2026 Q4 (current)
$150.33
Unchanged since Jan 1, 2021
24 quarterly CLFS releases on file, first CLFS 2021 Q1. A code missing from a quarter wasn’t on that release.
81338 compared with similar tests
- 81339MPL sequencingExon 10 sequence analysis$185.20
- 81338 targets common MPL variants; 81339 describes MPL exon 10 sequencing.
- 81270JAK2 testV617F variant$91.66
- 81270 analyzes JAK2 rather than MPL. Select the code for the gene analysis performed.
- 81219CALR testingCommon exon 9 variants$121.63
- 81219 analyzes CALR rather than MPL. Select the code for the gene analysis performed.
81338 billing questions
When is this code appropriate instead of 81339?
Use 81338 for analysis of common MPL variants. Code 81339 describes MPL exon 10 sequencing.
Which MPL changes does this analysis target?
It targets common variants, including codon 515 changes such as W515A, W515K, W515L, and W515R.
How does this test fit into a myeloproliferative neoplasm workup?
It can support evaluation of suspected myeloproliferative disorders, including essential thrombocythemia and myelofibrosis. JAK2 or CALR analysis may also be part of the workup.
How does Medicare pay this test?
Medicare pays it through the CLFS using one national amount, without locality or office-versus-facility adjustment.
Where this amount comes from
FeeBase reads lab amounts directly from the CMS Clinical Laboratory Fee Schedule file for the quarter: one row per code, with its payment indicator and national amount. Contractor-priced tests are labeled, never given a made-up amount. Amounts are Medicare payment limits, not a patient’s bill or a commercial rate.
CMS CLFS 2026 Q4 · effective Oct 1, 2026 through the day before Jan 1, 2027
Show the CMS file line behind this amount
Fee sheets · Coming soon
Put 81338 and the rest of your codes on one sheet
Your codes at your locality, with payer contracts beside Medicare.
Join the waitlist